360 lines
8.3 KiB
C
360 lines
8.3 KiB
C
/*
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* STMicroelectronics uvis25 sensor driver
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*
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* Copyright 2017 STMicroelectronics Inc.
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*
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* Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
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*
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* Licensed under the GPL-2.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/device.h>
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#include <linux/iio/sysfs.h>
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#include <linux/delay.h>
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#include <linux/pm.h>
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#include <linux/interrupt.h>
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#include <linux/irqreturn.h>
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#include <linux/iio/trigger.h>
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#include <linux/iio/trigger_consumer.h>
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#include <linux/iio/triggered_buffer.h>
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#include <linux/iio/buffer.h>
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#include <linux/regmap.h>
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#include "st_uvis25.h"
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#define ST_UVIS25_REG_WHOAMI_ADDR 0x0f
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#define ST_UVIS25_REG_WHOAMI_VAL 0xca
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#define ST_UVIS25_REG_CTRL1_ADDR 0x20
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#define ST_UVIS25_REG_ODR_MASK BIT(0)
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#define ST_UVIS25_REG_BDU_MASK BIT(1)
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#define ST_UVIS25_REG_CTRL2_ADDR 0x21
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#define ST_UVIS25_REG_BOOT_MASK BIT(7)
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#define ST_UVIS25_REG_CTRL3_ADDR 0x22
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#define ST_UVIS25_REG_HL_MASK BIT(7)
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#define ST_UVIS25_REG_STATUS_ADDR 0x27
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#define ST_UVIS25_REG_UV_DA_MASK BIT(0)
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#define ST_UVIS25_REG_OUT_ADDR 0x28
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static const struct iio_chan_spec st_uvis25_channels[] = {
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{
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.type = IIO_UVINDEX,
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.address = ST_UVIS25_REG_OUT_ADDR,
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.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
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.scan_index = 0,
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.scan_type = {
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.sign = 'u',
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.realbits = 8,
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.storagebits = 8,
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},
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},
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IIO_CHAN_SOFT_TIMESTAMP(1),
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};
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static int st_uvis25_check_whoami(struct st_uvis25_hw *hw)
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{
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int err, data;
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err = regmap_read(hw->regmap, ST_UVIS25_REG_WHOAMI_ADDR, &data);
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if (err < 0) {
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dev_err(regmap_get_device(hw->regmap),
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"failed to read whoami register\n");
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return err;
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}
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if (data != ST_UVIS25_REG_WHOAMI_VAL) {
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dev_err(regmap_get_device(hw->regmap),
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"wrong whoami {%02x vs %02x}\n",
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data, ST_UVIS25_REG_WHOAMI_VAL);
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return -ENODEV;
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}
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return 0;
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}
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static int st_uvis25_set_enable(struct st_uvis25_hw *hw, bool enable)
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{
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int err;
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err = regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL1_ADDR,
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ST_UVIS25_REG_ODR_MASK, enable);
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if (err < 0)
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return err;
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hw->enabled = enable;
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return 0;
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}
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static int st_uvis25_read_oneshot(struct st_uvis25_hw *hw, u8 addr, int *val)
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{
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int err;
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err = st_uvis25_set_enable(hw, true);
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if (err < 0)
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return err;
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msleep(1500);
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/*
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* in order to avoid possible race conditions with interrupt
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* generation, disable the sensor first and then poll output
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* register. That sequence guarantees the interrupt will be reset
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* when irq line is unmasked
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*/
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err = st_uvis25_set_enable(hw, false);
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if (err < 0)
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return err;
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err = regmap_read(hw->regmap, addr, val);
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return err < 0 ? err : IIO_VAL_INT;
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}
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static int st_uvis25_read_raw(struct iio_dev *iio_dev,
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struct iio_chan_spec const *ch,
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int *val, int *val2, long mask)
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{
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int ret;
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ret = iio_device_claim_direct_mode(iio_dev);
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if (ret)
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return ret;
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switch (mask) {
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case IIO_CHAN_INFO_PROCESSED: {
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struct st_uvis25_hw *hw = iio_priv(iio_dev);
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/*
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* mask irq line during oneshot read since the sensor
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* does not export the capability to disable data-ready line
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* in the register map and it is enabled by default.
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* If the line is unmasked during read_raw() it will be set
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* active and never reset since the trigger is disabled
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*/
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if (hw->irq > 0)
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disable_irq(hw->irq);
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ret = st_uvis25_read_oneshot(hw, ch->address, val);
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if (hw->irq > 0)
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enable_irq(hw->irq);
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break;
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}
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default:
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ret = -EINVAL;
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break;
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}
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iio_device_release_direct_mode(iio_dev);
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return ret;
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}
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static irqreturn_t st_uvis25_trigger_handler_thread(int irq, void *private)
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{
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struct st_uvis25_hw *hw = private;
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int err, status;
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err = regmap_read(hw->regmap, ST_UVIS25_REG_STATUS_ADDR, &status);
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if (err < 0)
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return IRQ_HANDLED;
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if (!(status & ST_UVIS25_REG_UV_DA_MASK))
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return IRQ_NONE;
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iio_trigger_poll_chained(hw->trig);
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return IRQ_HANDLED;
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}
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static int st_uvis25_allocate_trigger(struct iio_dev *iio_dev)
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{
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struct st_uvis25_hw *hw = iio_priv(iio_dev);
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struct device *dev = regmap_get_device(hw->regmap);
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bool irq_active_low = false;
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unsigned long irq_type;
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int err;
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irq_type = irqd_get_trigger_type(irq_get_irq_data(hw->irq));
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switch (irq_type) {
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case IRQF_TRIGGER_HIGH:
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case IRQF_TRIGGER_RISING:
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break;
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case IRQF_TRIGGER_LOW:
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case IRQF_TRIGGER_FALLING:
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irq_active_low = true;
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break;
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default:
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dev_info(dev, "mode %lx unsupported\n", irq_type);
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return -EINVAL;
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}
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err = regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL3_ADDR,
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ST_UVIS25_REG_HL_MASK, irq_active_low);
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if (err < 0)
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return err;
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err = devm_request_threaded_irq(dev, hw->irq, NULL,
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st_uvis25_trigger_handler_thread,
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irq_type | IRQF_ONESHOT,
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iio_dev->name, hw);
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if (err) {
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dev_err(dev, "failed to request trigger irq %d\n",
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hw->irq);
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return err;
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}
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hw->trig = devm_iio_trigger_alloc(dev, "%s-trigger",
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iio_dev->name);
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if (!hw->trig)
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return -ENOMEM;
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iio_trigger_set_drvdata(hw->trig, iio_dev);
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hw->trig->dev.parent = dev;
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return devm_iio_trigger_register(dev, hw->trig);
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}
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static int st_uvis25_buffer_preenable(struct iio_dev *iio_dev)
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{
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return st_uvis25_set_enable(iio_priv(iio_dev), true);
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}
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static int st_uvis25_buffer_postdisable(struct iio_dev *iio_dev)
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{
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return st_uvis25_set_enable(iio_priv(iio_dev), false);
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}
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static const struct iio_buffer_setup_ops st_uvis25_buffer_ops = {
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.preenable = st_uvis25_buffer_preenable,
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.postenable = iio_triggered_buffer_postenable,
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.predisable = iio_triggered_buffer_predisable,
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.postdisable = st_uvis25_buffer_postdisable,
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};
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static irqreturn_t st_uvis25_buffer_handler_thread(int irq, void *p)
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{
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u8 buffer[ALIGN(sizeof(u8), sizeof(s64)) + sizeof(s64)];
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struct iio_poll_func *pf = p;
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struct iio_dev *iio_dev = pf->indio_dev;
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struct st_uvis25_hw *hw = iio_priv(iio_dev);
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int err;
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err = regmap_read(hw->regmap, ST_UVIS25_REG_OUT_ADDR, (int *)buffer);
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if (err < 0)
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goto out;
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iio_push_to_buffers_with_timestamp(iio_dev, buffer,
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iio_get_time_ns(iio_dev));
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out:
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iio_trigger_notify_done(hw->trig);
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return IRQ_HANDLED;
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}
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static int st_uvis25_allocate_buffer(struct iio_dev *iio_dev)
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{
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struct st_uvis25_hw *hw = iio_priv(iio_dev);
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return devm_iio_triggered_buffer_setup(regmap_get_device(hw->regmap),
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iio_dev, NULL,
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st_uvis25_buffer_handler_thread,
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&st_uvis25_buffer_ops);
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}
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static const struct iio_info st_uvis25_info = {
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.read_raw = st_uvis25_read_raw,
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};
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static int st_uvis25_init_sensor(struct st_uvis25_hw *hw)
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{
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int err;
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err = regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL2_ADDR,
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ST_UVIS25_REG_BOOT_MASK, 1);
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if (err < 0)
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return err;
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msleep(2000);
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return regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL1_ADDR,
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ST_UVIS25_REG_BDU_MASK, 1);
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}
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int st_uvis25_probe(struct device *dev, int irq, struct regmap *regmap)
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{
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struct st_uvis25_hw *hw;
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struct iio_dev *iio_dev;
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int err;
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iio_dev = devm_iio_device_alloc(dev, sizeof(*hw));
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if (!iio_dev)
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return -ENOMEM;
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dev_set_drvdata(dev, (void *)iio_dev);
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hw = iio_priv(iio_dev);
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hw->irq = irq;
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hw->regmap = regmap;
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err = st_uvis25_check_whoami(hw);
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if (err < 0)
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return err;
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iio_dev->modes = INDIO_DIRECT_MODE;
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iio_dev->dev.parent = dev;
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iio_dev->channels = st_uvis25_channels;
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iio_dev->num_channels = ARRAY_SIZE(st_uvis25_channels);
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iio_dev->name = ST_UVIS25_DEV_NAME;
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iio_dev->info = &st_uvis25_info;
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err = st_uvis25_init_sensor(hw);
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if (err < 0)
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return err;
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if (hw->irq > 0) {
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err = st_uvis25_allocate_buffer(iio_dev);
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if (err < 0)
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return err;
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err = st_uvis25_allocate_trigger(iio_dev);
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if (err)
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return err;
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}
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return devm_iio_device_register(dev, iio_dev);
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}
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EXPORT_SYMBOL(st_uvis25_probe);
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static int __maybe_unused st_uvis25_suspend(struct device *dev)
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{
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struct iio_dev *iio_dev = dev_get_drvdata(dev);
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struct st_uvis25_hw *hw = iio_priv(iio_dev);
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return regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL1_ADDR,
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ST_UVIS25_REG_ODR_MASK, 0);
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}
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static int __maybe_unused st_uvis25_resume(struct device *dev)
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{
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struct iio_dev *iio_dev = dev_get_drvdata(dev);
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struct st_uvis25_hw *hw = iio_priv(iio_dev);
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if (hw->enabled)
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return regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL1_ADDR,
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ST_UVIS25_REG_ODR_MASK, 1);
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return 0;
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}
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const struct dev_pm_ops st_uvis25_pm_ops = {
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SET_SYSTEM_SLEEP_PM_OPS(st_uvis25_suspend, st_uvis25_resume)
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};
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EXPORT_SYMBOL(st_uvis25_pm_ops);
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MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>");
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MODULE_DESCRIPTION("STMicroelectronics uvis25 sensor driver");
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MODULE_LICENSE("GPL v2");
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